These are awesome! I based this recipe on my girlfriend Yael Eisenberg's famous cookies. I make this version in 4-ounce disposable aluminum muffin tins. The cookies come out of them very easily. However, each time I go to buy them, the sizes are different from store-to-store. This means they will vary in volume, but you really can't ruin this dish - just watch baking times. Smaller tins will bake faster and you want these a bit underdone. Larger tins can be used for a 2-person portion; just use more dough and bake slightly longer. If you prepare to molten cookies in 4-inch ceramic ramekins, the cookies will be harder to remove but just as yummy, so just serve right in the ramekin. You can ever top them off with some ice cream. Just warn your friends that the ramekin will be warm to the touch.

You can make the dough in advance and keep in the fridge so that you can enjoy this treat at a moment's notice! If serving for Friday night, bake right before Shabbos and keep warm on a blech or warming tray.

In the bowl of a stand mixer, at medium-low speed, mix the butter or margarine with the sugar and brown sugar. Raise the speed to medium-high and mix until creamy, light, and fluffy. Turn the speed down a little. Add the vanilla and eggs. Mix to incorporate.

Add half of the four mixture. Mix. Add the remaining flour mixture and mix until just combined. Mix in the chocolate chips.

Spray the aluminum tins with nonstick cooking spray.

Fill each muffin cup or ramekin a quarter of the way with a large, ping=pong-ball-size ball of cookie dough. Flatten slightly to cover the bottom. Stack 2 chocolate squares in the center. Cover with a second walnut-sized ball of cookie dough, flattening it to completely cover the chocolate.

Place onto a cookie sheet and bake until tips are golden brown. Do not overbake or the end result will be doughy, not gooey. The baking time will vary from 20-25 minutes depending on the size of the tin or ramekin and the amount of dough you needed to fill it. Your are looking for the tops to be golden and not wet-looking.

If using aluminum tins, turn each cookies out onto a plate. Serve warm.